1. Field of the Invention
The present invention relates to a band for timepiece and a wristwatch in which this band has been detachably attached to a case band.
2. Description of the Prior Art
Hitherto, there is known a technique detachably attaching the band to the case band of the wristwatch without using an exclusive tool (for example, refer to Patent Document 1).
In this technique of the Patent Document 1, a metal plate having two curl parts is attached to an end part of a leather band, and a spring bar is provided while extending over the two curl parts. The spring bar has a handle being bent approximately like the V letter in an intermediate part of a spring wire material, and one end and the other end, which are bent so as to become mutually remote from this handle. Both ends of this spring bar are individually inserted into the two curl parts and rotatably held, and the handle is disposed between the two curl parts. And, in one of the two curl parts, there are provided a slant face causing the handle to slide widely and narrowly, and a taper face holding the handle in a narrow width end of this slant face under a contraction state.
The one end of the spring bar consisting of the spring wire material is always protruded from the curl part which holds the one end. In contrast to this, the other end of the spring bar is protruded from the other curl part by the fact that the handle widens following upon the fact that the handle is brought down to a back face of the band by being rotated, and is immersed into the other curl part by the fact that the handle becomes the contraction state following upon the fact that the handle is raised with respect to the back face of the band by being rotated reversely to the former.
Accordingly, by rotating the handle of the spring bar, the end of this spring bar can be put in and taken out of a hole provided in a bow foot of the case band. For this reason, the band can be attached to and detached from the case band without using the exclusive tool.
<Patent Document 1> Japanese Utility Model No. 3042321 Gazette
In a case where a spring property of the spring bar formed by bend-working the spring wire material, whose elastic deformation is possible, is strong, there decreases an operability when raising the handle of the spring bar. Reversely to this, in a case where the spring property of the spring bar is weak, there decreases a reliability for attaching and holding the band to the case band with a predetermined strength. The spring property of the spring bar is generally large in its dispersion because the bend working of the handle of the spring bar influences as well. For this reason, in ensuring both of an easy attachment/detachment operability of the band with respect to the case band and a sufficient attachment strength, the technique of the Patent Document 1 is not desirable.
Further, there is considered the fact that the handle of the spring bar existing along a back side of the band contacts with a user's wrist during use and, in this case, there is the fact that a use feeling is impaired.
Moreover, under a state that the band having been detached from the case band is kept in custody, it is normal that the handle of the spring bar is made into a state of extending along the back face of the band. For this reason, when attaching the band to the case band of the wristwatch, there becomes necessary a work for immersing the movable end of the spring bar into the curl part holding this end, by once raising the handle. Therefore, a work for attaching the band to the case band is comparatively troublesome as well.